aws-beam/aws-elixir

Error when I try to reach MTurk

Closed this issue · 10 comments

cskaandorp commented

Hey people,

I am very happy with your package, but something weird happens when I try to reach MTurk:

iex(4)> AWS.MTurk.get_account_balance(client, %{})
** (ArgumentError) argument error
    (crypto 4.8.2) crypto.erl:932: :crypto.hmac/3
    (aws 0.7.0) lib/aws/request.ex:438: AWS.Request.Internal.signing_key/4
    (aws 0.7.0) lib/aws/request.ex:232: AWS.Request.sign_v4/6
    (aws 0.7.0) lib/aws/request.ex:40: AWS.Request.request_post/5

If something is wrong with roles, authentication I've seen different errors. This is is caused by Erlang's crypto module and I haven't got the foggiest of what I have done wrong. I am using plug_crypto 1.2.2.
Could you please help me out here

thanks!

Cspr

philss commented

hey @cskaandorp 👋
can you try to use the version from GitHub?

{:aws, github: "aws-beam/aws-elixir", branch: "master"}

The problem is that :crypto.hmac/3 was removed/renamed in OTP 24. This is fixed, but not released yet.

cskaandorp commented

Thanks for the quick reply! Appreciate it!

Now I am getting this error:

iex(3)> AWS.MTurk.get_account_balance(client, %{})
** (ErlangError) Erlang error: {:badarg, {'mac.c', 179}, 'Bad text'}
    (crypto 4.8.2) :crypto.mac_nif(:hmac, :sha256, <<181, 138, 134, 196, 133, 184, 250, 190, 176, 78, 35, 182, 153, 150, 63, 12, 41, 149, 230, 154, 131, 138, 69, 211, 217, 63, 150, 179, 112, 174, 18, 183>>, nil)
    (aws 0.7.0) lib/aws/signature.ex:186: AWS.Signature.signing_key/2
    (aws 0.7.0) lib/aws/signature.ex:28: AWS.Signature.sign_v4/6
    (aws 0.7.0) lib/aws/request.ex:43: AWS.Request.request_post/5
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philss commented

@cskaandorp can you tell me the version of Erlang and Elixir that you have installed?

cskaandorp commented

Erlang/OTP 23 [erts-11.1.6] [source] [64-bit] [smp:16:16] [ds:16:16:10] [async-threads:1] [hipe] [dtrace]
Elixir 1.11.3 (compiled with Erlang/OTP 23)

philss commented

@cskaandorp thanks! I will try to reproduce the error. But before that, can you check if you set the region for your client? Seems that region or service is nil when we are trying to generated the signing key.

cskaandorp commented

Hey @philss, this is my full code:

iex(2)> client = AWS.Client.create(
...(2)>     "XXXXXX", 
...(2)>     "YYYYYY", 
...(2)>     "us-east-1"
...(2)> )

iex(3)> client = %AWS.Client{ client | endpoint: "https://mturk-requester-sandbox.us-east-1.amazonaws.com" }

iex(4)> AWS.MTurk.get_account_balance(client, %{})                     
** (ErlangError) Erlang error: {:badarg, {'mac.c', 179}, 'Bad text'}
    (crypto 4.8.2) :crypto.mac_nif(:hmac, :sha256, <<181, 138, 134, 196, 133, 184, 250, 190, 176, 78, 35, 182, 153, 150, 63, 12, 41, 149, 230, 154, 131, 138, 69, 211, 217, 63, 150, 179, 112, 174, 18, 183>>, nil)
    (aws 0.7.0) lib/aws/signature.ex:186: AWS.Signature.signing_key/2
    (aws 0.7.0) lib/aws/signature.ex:28: AWS.Signature.sign_v4/6
    (aws 0.7.0) lib/aws/request.ex:43: AWS.Request.request_post/5

I sure hope I haven't made some stupid mistake. Thanks for getting into this.

Cspr

philss commented

@cskaandorp I fixed in 07017ef, but I think there is another problem unrelated to the signature. Please try again pointing to master, and then let me know if this works for you :)

cskaandorp commented

Hey @philss

Thanks so much for your effort. I have updated the package:

(anaconda3) ~/Work/mturk_client $ mix deps.update --all
* Updating aws (https://github.com/aws-beam/aws-elixir.git - origin/master)

And it seems there is progression:

iex(7)> AWS.MTurk.get_account_balance(client, %{})
{:error, :nxdomain}

I've tried both with https://mturk-requester-sandbox.us-east-1.amazonaws.com and https://amazonaws.com. I have to admit that I am out of my depth here. Might be that I am barking up the wrong tree with my request.

Cspr

philss commented

@cskaandorp I tried to set the endpoint to "us-east1.amazonaws.com" and it works! I mean, technically it works, because I don't have access to MTurk.
Can you try this?

client = %{client | endpoint: "us-east-1.amazonaws.com"}
AWS.MTurk.get_account_balance(client, %{})

PS: If you are trying to use the sandbox, then you need to create a new service module with the correct metadata. Something like this:

defmodule AWS.MTurkSandbox do
  alias AWS.Client
  alias AWS.Request

  def metadata do
    original = AWS.MTurk.metadata()

    %{original | endpoint_prefix: "mturk-requester-sandbox"}
  end

  def get_account_balance(%Client{} = client, input, options \\ []) do
    Request.request_post(client, metadata(), "GetAccountBalance", input, options)
  end
end

You can copy the functions from the original MTurk module at lib/aws/generated/mturk.ex from this project.
ref: https://requester.mturk.com/developer/sandbox

cskaandorp commented

@philss somehow I have missed your post. Thank you, and the rest of the group, so much for your comments, fix and the package. It is all working fine and I am working with it as we speak. Appreciate it!!

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